In motor vehicle body construction it has always been desirable to save weight. However, any reduction in weight must not be achieved at the expense of body characteristics in terms of stability, desired rigidity and, last but not least, mountability in the context of robot-supported production lines. In particular those body regions which because of their stability characteristics in the case of accidents are to absorb the forces that are typically encountered in accidents are the subject of numerous different design efforts. Especially sills and structural members of vehicle bodies have been varied many times.
The principal significance of the sill as a vehicle body element consists of absorbing loads both during head-on crashes and during lateral impact collisions. In lateral impact collisions balanced stiffness is desired that makes possible a targeted reduction of the impact energy. Thus, multi-component sills with a closed profile are often designed with ribs, stiffening elements or generally load transmission elements in their interior in order to, in particular, locally improve buckling resistance, as has been disclosed, for example, in DE 11 2008 002 515 T5. During manufacture the sill geometry is thus of significance inasmuch as it determines the manner, especially the particular direction, and the particular production step during which insertion of load transmission elements is to take place.
The above is associated with disadvantages in that, as a result of the focus on the static and dynamic requirements, the forms of load transmission elements and the surrounding deformation contour of the sill are as a rule designed so that the deformation contour of the sill needs to be closed before the usual coating by means of cathodic immersion paint coating can take place. Any insertion of load transmission elements after immersion paint coating is not possible without incurring undesirable disadvantages in the overall production process. As a result of this the choice of materials for the load transmission elements is limited. Generally speaking the sill is joined to or beside a support element mounted to the body-in-white. Both molded parts significantly contribute to the weight and the material used in vehicle body construction.